Adhesive for bonding membranes made of soft pvc

Abstract

An epoxy resin adhesive is used for bonding a membrane made of soft PVC to a further substrate, wherein the curing-agent component of the adhesive includes at least one amine A1 having at least one dimethylamino group and at least one amine hydrogen, and at least one further amine A2 having at least three amine hydrogens, and the curing-agent component includes, based on the total of all the liquid or dissolved constituents contained in the curing-agent component, an amine A1 content of 10 to 45 wt. %. The use allows bonding of untreated membranes made of soft PVC to form a stable, water-resistant adhesive bond and is particularly suitable for sealing tunnels, foundations and roofs.

1 . A method for bonding a soft PVC membrane to a further substrate, comprising the steps of:
 providing a two-component adhesive composition comprising a resin component and a curing agent component,   mixing the resin component and the curing agent component and any further components present in the adhesive by a suitable method,   applying the mixed adhesive to the soft PVC membrane and/or to the further substrate,   joining the substrates within the open time of the adhesive, and   curing the adhesive,   wherein the adhesive comprises
 a resin component comprising at least one epoxy resin and 
 a curing agent component comprising
 (a) at least one amine A1 having at least one dimethylamino group and at least one amine hydrogen, and 
 (b) at least one further amine A2 which has at least three amine hydrogens and is free of dimethylamino groups, 
 
   wherein the curing agent component, based on the sum total of all liquid or dissolved constituents present in the curing agent component, has a content of amines A1 of 10% to 45% by weight.   
     
     
         2 . The method as claimed in  claim 1 , wherein the resin component contains at least one aromatic liquid epoxy resin. 
     
     
         3 . The method as claimed in  claim 1 , wherein the amine A1 is selected from the group consisting of 2-dimethylaminoethylamine, 3-dimethylaminopropylamine, 4-dimethylaminobutylamine, 6-dimethylaminohexylamine, 2-(2-dimethylaminoethylamino)ethylamine, 2-(3-dimethylaminopropylamino) ethylamine, 3-(2-dimethylaminoethylamino)propylamine, 3-(3-dimethylaminopropylamino) propylamine, N-(3-dimethylaminopropyl)-1,3-bis(aminomethyl)benzene, N-(3-dimethylaminopropyl)-1,4-bis(aminomethyl)benzene, 2,4,6-tris(4-dimethylamino-2-azabutyl)phenol, bis(2-dimethylaminoethyl)amine, bis(3-dimethylaminopropyl)amine and bis(6-dimethylaminohexyl)amine. 
     
     
         4 . The method as claimed in  claim 1 , wherein the number of amine hydrogen equivalents from amines A1 based on the total number of amine hydrogen equivalents in the curing agent component is in the range from 20% to 60%. 
     
     
         5 . The method as claimed in  claim 1 , wherein the amine A2 is selected from the group consisting of 1,5-diamino-2-methylpentane, hexane-1,6-diamine, 2,2(4),4-trimethylhexane-1,6-diamine, 2-butyl-2-ethylpentane-1,5-diamine, isophoronediamine, 1,3-bis(aminomethyl)benzene, 1,4-bis(aminomethyl)benzene, 2,5-bis(aminomethyl)furan, 2,5-bis(aminomethyl)tetrahydrofuran, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 2(4)-methyl-1,3-diaminocyclohexane, 2,5(2,6)-bis (aminomethyl)bicyclo[2.2.1]heptane, N-benzylethane-1,2-diamine, N-furfurylethane-1,2-diamine, N-tetrahydrofurfurylethane-1,2-diamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, N-(2-aminoethyl) propane-1,3-diamine, N,N′-bis (3-aminopropyl) ethylenediamine, bis (1,6-hexylene) triamine, phenalkamines, phenalkamides, polyamidoamines, amine-functional adducts of the amines mentioned with epoxides, and combinations of two or more of these amines. 
     
     
         6 . The method as claimed in  claim 1 , wherein the amine A2 present is at least one amine A2-1 having an amine hydrogen equivalent weight of at least 80 g/eq. 
     
     
         7 . The method as claimed in  claim 6 , wherein the amine A2 present is a combination of at least one amine A2-1 and at least one amine A2-2 having two primary amino groups and four amine hydrogens. 
     
     
         8 . The method as claimed in  claim 1 , wherein the curing agent component contains a combination of 3-(3-dimethylaminopropylamino)propylamine, isophoronediamine and at least one amine selected from phenalkamines, phenalkamides and amine-functional adducts of N-benzylethane-1,2-diamine with at least one aromatic liquid epoxy resin. 
     
     
         9 . The method as claimed in  claim 1 , wherein the adhesive contains at least one further ingredient selected from thinners, fillers, accelerators and surface-active compounds. 
     
     
         10 . The method as claimed in  claim 1 , wherein the adhesive contains, based on 100 parts by weight of the sum total of all constituents containing epoxy and amine groups, not more than 30 parts by weight, of thinner. 
     
     
         11 . The method as claimed in  claim 1 , wherein the adhesive contains, based on the overall adhesive, 60% to 90% by weight, of mineral fillers. 
     
     
         12 . The method as claimed in  claim 1 , wherein the adhesive contains, based on the overall adhesive,
 10% to 20% by weight of aromatic liquid epoxy resins,   1% to 4% by weight of reactive diluent containing epoxy groups,   3-(3-dimethylaminopropylamino)propylamine,   isophoronediamine,   at least one amine A2-1 having an amine hydrogen equivalent weight of at least 80 g/eq,   60% to 90% by weight of mineral fillers   
       and optionally further ingredients. 
     
     
         13 . The method as claimed in  claim 1 , wherein the further substrate is selected from soft PVC, polyolefin, modified polyethylene, concrete, mortar, cement screed, fiber cement, brick, tile, natural stone, steel, polyvinylidene fluoride-coated metals and further plastics. 
     
     
         14 . An adhesive bond obtained from the use as claimed in  claim 1 . 
     
     
         15 . The adhesive bond as claimed in  claim 14 , wherein the peel strength value in each case is at least 1 N/mm, determined both after a) curing under standard climatic conditions for 7 days and b) curing under standard climatic conditions for 7 days, followed by storage at 70° C. and 100% relative humidity for 28 days, followed by storage under standard climatic conditions for 3 days, where, if the soft PVC membrane has been bonded to a further membrane, peel strength is determined to DIN EN 14173 at a strain rate of 100 mm/min, and where, if the soft PVC membrane has been bonded to a solid surface, peel strength is determined in accordance with DIN EN 14173 at a strain rate of 100 mm/min with a strain angle of 90° between the soft PVC membrane and the solid surface.